WO 00/66872 discloses a rock cutting device whereby a stream of drilling fluid containing abrasive particles is ejected against the borehole bottom or borehole wall by a nozzle provided at a cutter head of the device.
A problem of the known device is that the direction of the ejected stream cannot be as optimal as desired in view of limitations regarding the position of the nozzle at the cutter head. For example in certain applications it is desirable that the ejected stream passes close to, and substantially parallel to, the borehole wall in order to accurately cut the borehole circumference. However, the position of the nozzle inwardly from the outer radius of the cutter head prevents such stream direction.